Conversely, my airline (737/757) tells us to use idle reverse only with most of the stopping coming from the brakes. This is undoubtedly what they've worked out is the most economical technique for our aircraft. And as canuckbirdstrike says, this has the benefit of allowing more reverse thrust if required. I may be wrong but I seem to remember reading that brake life also increases with a steady higher autobrake selection (2 or 3) as opposed to minimum autobrake. This would be another argument for the way its done in my airline.
PW